The present disclosure relates to an additive manufacturing system and, more particularly, to a workpiece manufactured by the additive manufacturing system having a particle separator and method of operation.
Traditional additive manufacturing systems (AMS) include, for example, Additive Layer Manufacturing (ALM) devices, such as Direct Metal Laser Sintering (DMLS), Selective Laser Melting (SLM), Laser Beam Melting (LBM) and Electron Beam Melting (EBM) that provide for the fabrication of complex metal, alloy, polymer, ceramic and composite structures by the freeform construction of turbine components, layer-by-layer. The principle behind additive manufacturing processes involves the selective melting of atomized precursor powder beds by a directed energy source, producing the lithographic build-up of the workpiece 60. The melting of the powder occurs in a small localized region of the energy beam, producing small volumes of melting, called melt pools, followed by rapid solidification, allowing for very precise control of the solidification process in the layer-by-layer fabrication of the workpiece 60. These devices are directed by three-dimensional geometry solid models developed in Computer Aided Design (CAD) software systems. The strategy of the scanning, power of the energy beam, residence time or speed, sequence of melting are directed by the embedded CAD system.
Significant effort is needed to improve the speed of additive manufacturing systems so that they can become a cost effective option to castings, and to improve the quality because AMS produced workpiece 60s suffer from several deficiencies resulting in poor material characteristics, such as porosity, melt ball formations, layer delamination, and uncontrolled surface coarseness and material compositions.
The AMS is useful in manufacturing complex and detailed workpieces. Unfortunately, such workpieces often require smooth surfaces for efficient operation not producible using an AMS; thus, additional, time consuming, and expensive machining or other more conventional steps may be required. Moreover, such surfaces may be internal and not accessible for machining In addition, many workpieces are under internal stresses during operation that limit surrounding environment exposure to heat and/or pressure. To address such stress concerns, it is desirable to change material densities or compositions at pre-selected locations in the workpiece thus making the workpiece less susceptible to the negative effects of the surrounding environment. Unfortunately, known AMS's are not capable of manufacturing such composition variances in a single workpiece.